Hot Reds

Credit: Mark Turner / Photo Library | Netherlands Flower Bulbs

Add an instant blaze of colour to the most sedate garden

Red flowers are often overlooked when creating a colour theme in our home gardens, perhaps because red is a hot colour and most of us are drawn to the softer hues. But red can spice up a bed or border any time of year, and it really comes into its own at the height of summer and through fall.

While the majority of plants described here are summer bloomers, there are some gems that flower in other seasons, so let’s start with spring.

A low, almost miniature, small-leaved evergreen shrub, ‘Hino-crimson’ azalea is an amazing hybrid of Japan-native Rhododendron obtusum. It is the abundance of the blooms, borne in trusses of two to three flowers from mid April to early May, each 3 cm (an inch or so) across, that makes it spectacular. In fact, the blossoms are so plentiful that at their peak they completely hide the shrub.

The overall height is 30 to 40 cm (12 to 16 in.), although mature plants can reach a width of a metre or more (3 ft.). Its size makes it ideal for townhouse and balcony gardens. It grows well in a pot but must be placed in an area with morning sun and afternoon shade. In the garden it is extremely happy in our acidic soil conditions but does appreciate a good spade or two of well-rotted leafy compost at planting time and a few inches of mulch annually in March. During the dry spells of summer it requires weekly watering, more often if grown in a container. But let me tell you: When this one is in bloom the whole neighbourhood will notice!

Tulips provide outstanding spring reds, particularly Tulipa ‘Miss Holland’. Its large, bowl-shaped flowers are an intense blood-red borne on stems 30 to 35 cm (12 to 14 in.) long. The ones pictured on page 26 have just been through a spring rainstorm but are still magnificent. Tulips prefer well-drained soil in an open sunny location and look their best planted in clumps of five or seven bulbs. Add a balanced organic bulb fertilizer to the bottom of the hole at planting time, and do remember to plant them deeper than a trowel’s depth so they can stay in the ground undisturbed year round, in a spot where their foliage can die back naturally each spring. Finally, be sure to fertilize tulips at flowering time, as this will help build up the bulbs’ energy for producing good blooms the following spring.

A May-flowering shrub well worth considering is Kalmia latifolia ‘Ostbo Red’. This cultivar gets its name from the unopened buds, which are bright red; the surprise comes when the buds open to vivid pink flowers. The combination of flowers and unopened buds is a real showstopper. Exercising my writer’s license, I say this one qualifies as a red!

David admires the red budsand pink flowers
of Kalmia latifolia ‘Ostbo Red’

In its native setting of the deciduous Carolinian forests of eastern North America, where it is commonly known as calico bush or mountain laurel, Kalmia latifolia, reaches a height of up to 3 m (9 ft.). On the Pacific Coast, however, the tallest I have seen is 2 m (6½ ft.).

The specimen pictured with me on the following page is growing in the afternoon shade of a maple in the North American section of the Alpine Garden at the UBC Botanical Garden. The soil there is extremely well drained, but plenty of leafy compost was added at planting time and these shrubs appreciate an annual spring leaf mulch.

Just as an aside, having mentioned leafy compost, the best source is city boulevards in the fall. Collect fallen leaves in a garbage pail when they are dry and run a line trimmer through them to break them up. Then compost the shredded leaves or keep them in plastic bags in a shed or garage until you need them for mulch in the spring.

Two absolutely smashing red plants for the perennial border in early summer are Oriental poppies and peonies. The Papaver orientale pictured in our lead photograph is very likely the cultivar ‘Allegro’. I absolutely adore these poppies; just waiting and watching for their buds to open is a magical experience.

I always think of Des Kennedy when writing or talking about poppies, as he jokingly calls them “holes.” If left unsupported, the entire plant collapses just as it is about to flower, with the stems lying along the ground and a big hole in the middle. And the holes can be quite large as the stems are about 65 cm (over 2 ft.) in length.

One way to deal with this is to save the nice, long (60 cm/2 ft. or so) twiggy branches pruned from trees and shrubs in winter/early spring, bundle them up and let them dry out. When the poppies start to send up new growth in spring, push the branches into the ground all around the plants. Of course, this does not look attractive right away, but we gardeners have patience; as the poppy grows, its foliage and flower stems hide the branches, which support the plant in a natural-looking way.

Paeonia lactiflora ‘Karl Rosenfeld’ is another of my favourite reds in the early-perennial category, with its large, truly double, bright deep-red blooms. Single peonies are self-supporting but the doubles need staking, as a good spring rain can saturate the blooms, causing stems to droop or break. Once established in a garden they are very long-lived plants.

As the season progresses, along comes Phlox paniculata ‘Starfire’, a tall border phlox with deep crimson-red flowers. The mature flowering stems of this phlox reach about a metre (40 in.) in height and the colour truly is stunning. Many coastal gardeners avoid planting phlox because it is so susceptible to powdery mildew. Some years the mildew is worse than others, but I wouldn’t let this stop you from growing these beauties in your garden. Powdery mildew can be somewhat controlled by spraying with a mixture of baking soda and water: use 5 ml (1 tsp.) of baking soda to 1 L (4 cups) of slightly soapy water (made up from bar soap, not dishwashing detergent).

Oriental poppies, peonies and border phlox all thrive in full sun and well-drained soil high in organic matter. Add a shovel or two of compost to the hole when planting. Each March, add a handful of organic, all-purpose fertilizer and 5 cm (2 in.) of fertile mulch.

If you love Crocosmia ‘Lucifer’, I guarantee you will adore Crocosmia × crocosmiiflora ‘Babylon’, a fairly new cultivar on the plant stage. It is shorter than ‘Lucifer’ at about 60 cm (2 ft.), and the abundant mango-red flowers with deep scarlet throats are a hummingbird’s dream come true! Crocosmias like a sunny spot and survive in relatively poor soil, although they certainly enjoy a top dressing of compost each spring.

Crocosmia x crocosmiiflora ‘Babylon’

Another summer-bloomer, Echinacea purpurea must be one of the most talked-about garden introductions of the past few years. And it has turned out to be such a good plant that the hybridizers have had a field day crossing other species of the genus, resulting in two recent introductions that are magnificent. ‘Hot Lava’ is a true red form that looks more like the traditional coneflower, with a less protruding centre; ‘Hot Papaya’ has an amazing fully double centre. Both are excellent plants for dry soils and well suited to interior B.C. gardens, as they are hardy in zone 4 and up. These particular cultivars can be a challenge in coastal gardens as they require hot, sunny locations to perform well. For readers in the dryer regions of the interior, however, they are must-haves!

You can count on annuals for the most colour throughout summer. I particularly love African daisies (Arctotis), which are perfect for a long hot and dry spell. The one on the previous page is the cultivar ‘Flame’, and according to author Sarah Raven, it once thrived at the famous Sissinghurst Garden. Harold Nicholson, who created the garden with his wife Vita Sackville-West, bought a plant of ‘Flame’ in 1959 and propagated it to form broad sweeps of vibrant colour. Deadheading is key to keeping plants tidy. To continue them from year to year, make cuttings in September and overwinter plants on a sunny windowsill to be planted out next May.

For containers and hanging baskets, you can count on Verbena ‘Tukana’, which has smashing red flowers, and Calibrachoa, a petunia cousin that produces never-ending cascades of blooms and can tolerate more sun than the traditional petunias. Indeed, they need hot afternoon sun to bloom well. The one pictured on the previous page is ‘Superbells Red’. In our climate both are grown as annuals; if you have a greenhouse, they can be overwintered.

Annual salvias, often used in traditional bedding-plant schemes, are noted for their brilliant-scarlet hues. Salvia coccinea ‘Lady in Red’ reaches 45 cm (18 in.) in height with cherry-red flowers. Locate this one in a perennial border in front of earlier-flowering plants such as poppies, as it will keep on going right until frost.

And while on the subject of annuals, an old and sometimes forgotten favourite is the blanket flower. The wonderful brilliant-red hybrid Gaillardia pulchella ‘Red Plume’ will certainly brighten up any border from midsummer through fall.

And speaking of fall, many perennials also put on a show in this season. One old favourite, the tall border sedum (Sedum spectabile), has been crossed with S. telephium to create a hybrid called ‘Class Act’ with yellow buds that open to red-purple flowers. The ideal site for this colour sensation is a well-drained sunny spot at the front of a mixed bed or border.

Finally, one stunner for the shade is Heuchera ‘Autumn Leaves’. This amazing selection has dark-red new growth in spring, followed by orange-red mature foliage in summer, which then takes on a bronzy reddish hue in fall.

So there you have it: a year-round selection of ravishing red beauties to put a little fire into your garden.

David Tarrant is a well-known gardening expert, author, and television host. Read his blog here

The following plants are hardy to the zone number indicated (turn to page 6 for our zone chart): Crocosmia × crocosmiiflora ‘Babylon’ – zone 6 • Echinacea ‘Hot Papaya’, ‘Hot Lava’ – zone 4 • Heuchera ‘Autumn Leaves’ – zone 4 • Kalmia latifolia ‘Ostbo Red’ – zone 5 • Paeonia lactiflora ‘Karl Rosenfeld’ – zone 4 • Papaver orientale – zone 4 • Phlox paniculata ‘Starfire’ – zone 4 • Rhododendron ‘Hino-crimson’ – zone 6 • Sedum ‘Class Act’ – zone 4 • Tulipa ‘Miss Holland’ – zone 4